3 - Fight or Flight Response

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  • Often the endocrine & ANS work in parallel during a STRESSFUL EVENT - e.g. the FLIGHT or FIGHT RESPONSE
• Fight or Flight steps

  1. Situation is appraised & perceived as stressful

  2. When stressor is perceived hypothalamus alerted & triggers activity in the SYMPATHETIC BRANCH of the ANS

  3. The ANS changes from its normal resting state (the parasympathetic state) to the physiologically aroused sympathetic state

  4. This stimulates the adrenal medulla (which is part o the adrenal gland located just above the kidney) to release the stress hormone adrenaline AND indirectly the neurotransmitter noradrenaline into the bloodstream

  5. Adrenaline triggers physiological changes in target organs in the body & causes the flight or fight response (includes raised heart rate etc)

  6. Once the stressor/threat has passed the PARASYMPATHETIC NERVOUS SYSTEM returns to its resting state (called the rest & digest response). This acts as a brake and reduces the activities of the body that were increased by actions on the SYMPATHETIC branch
• Physiological Changes in fight or flight response

  • Raised heart rate
  • Pupils dilate
  • Increased breathing
  • Flushed face / pale skin
  • Unnecessary processes shut down & blood redistributed to other more key places (muscles & brain)
  • Racing thoughts
  • Sweaty palms
  • Decreased production of saliva - dry mouth
• Why

  Body can't maintain this increased level of activity for long periods as it takes too much energy
• What happens after a few minutes in the flight or fight response / when stressor/threat passes or is dealt with? 1


  1. The body can not maintain this increased level of activity for long periods of rime as it takes to much energy.
  2. SO after a few minutes OR when stressor/threat is passed/dealt with the parasympathetic nervous system is activated.
• What happens after a few minutes in the flight or fight response / when stressor/threat passes or is dealt with? CONT... 2

  3. It acts as a brake response by reducing the activities of the body (that were increased by actions on the sympathetic branch) e.g. Reduces heart rate, restores activity to digestive system

  4. This brings the body back to its normal resting state (called the rest & digest response)
• Sympathetic vs Parasympathetic State x6 differences

  Sympathetic vs Parasympathetic State x6 differences

  
• Raised heart rate - reason?

  • To increase O2 for respiration going to organs in blood.
  • Increasing heart rate = increases pumping which gives more blood flow and O2 to muscles for respiration = energy for flight or fight (quicker problem solving & thinking & ability to run or fight)
• Pupils dilate


  • See more stuff/surroundings/threat - let more light in = more observant = see threat
• Increased breathing - reason?

  • To increase O2 for respiration = energy for response
• Unnecessary processes shut down & blood redistributed to other more key places (muscles & brain)

  • More blood & O2 to more key organs so more respiration & energy in those key organs
  • Brain = energy = improved cognitive functions for complex decisions (where to run to, what to do)
  • Can cause dry mouth and nausea/butterflies (coz digestion is suppressed so energy go to more important places)
• Racing thoughts & sweaty palms

  • Racing thoughts = quick thinking helps evaluate danger & make rapid decisions
  • Sweaty palms = keeps us cool (when heart rate & blood flow increases = this will warm us)
• Flushed face / pale skin - reason?

  • Blood redirected to brain to increase blood flow to brain & other more important muscles to increase O2 supply & respiration in these areas and thus increase energy = improving cognitive functions for complex quick decisions
• Flight or Fight Steps?

  ?

  A) ?

  
• Fight or Flight steps
1


  1. Situation is appraised & perceived as stressful

  2. When stressor is perceived by hypothalamus, it activates the pituitary, the SYMPATHETIC BRANCH of the ANS is now alerted/active/aroused.

  3. The ANS changes from its normal resting state (the parasympathetic state) to the physiologically aroused sympathetic state

  4. This stimulates the adrenal medulla (which is part o the adrenal gland located just above the kidney) to release the stress hormone adrenaline AND indirectly the neurotransmitter noradrenaline into the bloodstream
• Fight or Flight steps - 2


  5. Adrenaline triggers physiological changes in target organs in the body & causes the flight or fight response (includes raised heart rate etc - an aroused state). This response is IMMEDIATE & AUTOMATIC (this response happens the instant a threat is perceived).

  6. Once the stressor/threat has passed the PARASYMPATHETIC NERVOUS SYSTEM returns to its resting state (called the rest & digest response). This acts as a brake and reduces the activities of the body that were increased by actions on the SYMPATHETIC branch.